Motor-meter.



Patented Apr. '29, I902. T. DUNCAN.-

MOTOR METER.

(Application filed Sept. 23, 189 9. Renewed Jan. 6, 1902.)

2 Sheets$hoet I.

(No Model.)

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Patented Apr. 29, I902.

T. DUNCAN. MOTOR METER.

(Application filed Sept. 28, 1899. Renewed Jan. 6, 1902.,

2 Sheets-Sheet 2.

(No Model.)

Wibwwaea NITED STATES PATENT FFICE'.

THOMAS DUNCAN, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE SIEMENS &; HALSKEELECTRIC COMPANY OF AMERICA, OF CHICAGO, ILLINOIS, A

CORPORATION OF ILLINOIS.

MOTOR-METER.

SPECIFICATION forming part of Letters Patent No. 698,658, dated April29, 1902.

Application filed September 23, 1899. Renewed January 6,1902. Serial No.88.482. (No model.)

To all whom, it may concern.-

Be it known that I, THOMAS DUNCAN, a citizen of the United States,residing at Chicago,

in the county of Cook and State of Illinois, have invented a certain newand useful Improvement in Motor-Meters, (Case No. 3,) of which thefollowing is a full, clear, concise, and exact description, referencebeing had to the accompanying drawings, forming a part of thisspecification.

My invention relates to meters for measuring alternating currents, andhas for its object the provision of an improved motor-meter which iscapable of measuring and integrating the energy in a plurality ofalternating-current circuits.

In meters of this type two armatures are mounted upon a single spindle,and there is applied to this single spindle a single retarding device,such as a disk rotated in the field of a permanent magnet. Ininduction-meters of this class it is usual to obtain the'magnetic fieldwhich represents the electromotive force by connecting the shunt-circuitwhich produces this field to the circuit carrying one of the phases,while the series or ampere coils are connected directly in circuit withthe leads. The two leads of one phase, in series with one of which theseries coil is connected, carry a current ninety degrees ahead of thetwo leads to which the shuntcoil is connected. There is thereby produceda current through the series and shunt circuits, respectively, ninetydegrees apart, which is the necessary condition for the operation ofinduction-meters. I find, however, that due to the self-induction of thepressure-coils used to produce the magnetic field which represents thepressure the current lags beyond ninety degrees, and since the meter isobliged -to measure inductive loads an angle of exactly ninety degreesmust be obtained. To do this is the object of the apparatus of myinvention.

In this meter I employ mechanically-coupled armatures, one for eachcircuit, for operating the registering-train, each armature being ininductive relation to field-coils, each set of field-coils being soassociated with the circuits that the combined torque exerted thereby isproportional to the true energy of the circuits. Thus I am able toconstruct an integrating-meter in which a single reading shows theenergy in the work-conductors of the polyphase system ofalternating-current distribution.

A more precise understanding of the invention will be had by referenceto the accompanying drawings, illustrating the preferred embodiment ofmy invention, in which- Figure l is a diagrammatic view of thearrangement of my meter in its application to the four-wire system ofdistribution. Fig. 2 is a phase and vector diagram, showing the relationof the magnetism and current in the two circuits during the firsthalf-cycle. Fig. 3 isa diagrammatic view of the arrangement of myinvention in its application to a threewire system of distribution inwhich a common return-wire is used. Fig. i is a phase and vector diagramshowing the position and relation of the magnetism and current in thetwo circuits during the last half-cycle or from one hundred and eightydegrees to three hundred and sixty degrees.

Like parts are indicated by similarcharactors of reference throughoutthe different views.

Referring to Fig. 1, the armatures 1 and 16, while shown separate forthe sake of clearness, may be assumed to be mechanically coupledtogether, as indicated by dotted lines. I will explain the relation ofthe field-coils to the armatures principally with reference to thearmature 1 and the field-coils 2 and 3.

The series coil 2 is connected in series in the circuit 8 9, and if theload be non-inductive the current through it will be in phase with theelectromotive force represented by a in the vector diagram of Fig. 2.The shuntwinding 3 is connected to the leads 10 and 11,

.in which the phase is ninety degrees behind that of the leads 8 9. Dueto the inductance of the coil 3, this current and resultant magnetismare in excess of ninety degrees behind the phase of the current in 8 9and may be represented by the line b of Fig. 2. To get the magnetism inquadrature with the current represented by the line a, I employ atransformer A, whose primary winding 7 is connected with the circuit 89, which feeds the series coil 2. The secondary winding 6 of thetransformer is connected with the coil 4,-

which is in inductive relation with the shuntcoil 3, and in circuit withsaid coil in the secondary of the transformer is the adjustableresistance 5. force of the secondary of the transformer 6 is representedin the vector diagram by the line 0; but by reversing the direction ofthis current, so that it will be in opposition to the currentin coil 3,the phase relation of the secondary circuit of the transformer to thatof the coil 3 is shown by the line 0. By adjusting the resistance 5until its magnitude is such that the resultant of the currents ,in 3-and 4 gives the line d as the resultant magnetism of the coils 3 and 4the desiredresult of producing a magnetism in quadrature with theimpressed electromotive force of the circuit 8 9 is secured.

Without specifically describing the other armature and its associatedfield-coils it will be apparent that all that has been said re-.

garding the motive part of the meter represented by the armature 1 andits associated of circuit 10 11 in the same Way as that alreadydescribed with reference to the first motive part of the armature. Inthis second motive part the line 61 of Fig. 2 represents the current, (anon-inductive load being assumed), The line e represents the currentthrough the coil 17; f, the secondary electromotive force in thesecondary coil 20 of the transformer and in the field-coil 18. The linef represents the current reversed in coil 18 in opposition to 17, and grepresents the resultant magnetism of the coils 17 18.

In Fig. 3 I have shown substantially the same combination of circuitsand apparatus as that shown in Fig. 1; but thecircuits 9 10' of Fig. 1are shown in Fig. as combined to constitute a common return. Thedescription already given of'the circuits and appa ratus of Fig. 1 applyto Fig. 3, with the modification necessary to the combination of thelines 9 and 10."

Inthe phaseand vector diagram of Fig. 4b, showing the position of thecurrents in the two circuits during the last half of cycle, (1represents the pressureof the circuit, including series coil 2;.b, thecurrent in coil ,3; c,

The induced electromotive in quadraturewith a, and assuming the line (2,representing the current in the coil 11; e, the magnetism of the coil17; f, that of coil 18 with current reversed, and g the resultantsecured by adjustment of the resistance 19 of the magnetism of coils 17and 18 in quadrature with (:1.

In the'foregoing description it will be seen that the torque of eachmotive part is applied to the spindle, so that the speed and torque ofthe combined motiveparts at any instant represent the true watts passingthrough the meter, whether it be either side alone or both sides thatare being operated.

I have not deemed it necessary to show the counting-traimthe retardingdevice, and the initial torquedevice, which are well under stood bythoseskilled in the art. While I have shown my invention as applied todiphase circuits, I do not wish to be limited to this application, as itwill be apparent to those skilled in the art that other applications ofthe invention are possible;

nor do I wish to be limited to the precise instrusecondary circuits ofsaid transformers adapted to modify the magnetism of the said pressure-windings to bring the same into quadrature with the impressedelectromotiveforce of the circuit including said series winding, apressure-winding of one motor member receiving current from the circuitsupplying current to the current-winding of the other motor member,substantially as described.

2. In a polyphase-current induction motormeter, the combination with twoor morearmatures coupled together, ofa current anda pressure winding ininductive relation with each of said armatures, each pressure-windingreceiving current from the circuit supplying the current-windingassociated with the other pressure-winding, the current in eachpressure-winding lagging beyond ninety degrees with relation to thepressure in the circuit including its associated current-winding, and asecond pressure-winding associated with each of the aforesaidpressure-windings and carrying current lagging less than ninety degreeswith relation to the pressure inthe circuit including its associatedcurrent-winding, whereby the magnetism due to said pressure-windings isbrought in quadrature with the electromotivc force of the circuitincluding said current-winding, described.

3. In a device of the class described, the combination with two or morearmatures coupled together, of a current and a pressure winding ininductive relation with each of said armatures, transformers havingtheir primaries connected inparallel in the circuits including saidcurrent-windings, a second pressure-winding in the secondary circuit ofeach of said transformers and adjusting resistances in series with saidlast-named windings, whereby the magnitude of the current in saidsecondary circuits may be modified and the magnetism of thepressure-windings be brought in quadrature with the impressedelectromotive force of the circuit including said current-coil, apressure-winding of one motor member receiving current from the circuitsupplying current to the current-wind ing of the other motor member,substantially as described.

4. In a polyphase-current induction motormeter, the combination with twomotive sets of windings each comprising a current and a pressurewinding. each pressure-winding receiving current from the circuitsupplying thecurrent-winding associated with the other pressure winding,the current in each pressure-winding lagging beyond ninety degrees withrelation to the pressure in the circuit including its associatedcurrent-winding, and a secondwinding associated with each of saidpressure-windings and carrying current lagsubstantially as ging lessthan ninety degrees with relation to the pressure in the circuitincluding its associated current-winding, whereby the magnetism due tosaid pressurewindings is brought in quadrature with the electromotiveforce of the circuit including said current winding, and a movableelement subjected,

to the action of said motive sets of windings, substantially asdescribed.-

5. In a polyphase-current induction motormeter, the combination with twomotive sets of windings each comprising a current and a pressurewinding, each pressure-winding receiving current from the circuitsupplying the current-winding associated with the otherpressure-winding, the current in each pressure-winding lagging beyondninety degrees with relation to the pressure in the circuit includingits associated current-winding and a second winding associated with eachof said pressure-windings and carrying current lagging less than ninetydegrees with relation to the pressure in the circuit including itsassociated current-winding, and meansincluded in series with each ofsaid second pressurewindings for adjusting the magnetism due thereto,whereby the magnetism due to said pressure-windings is brought inquadrature with-the electromotive force of the circuit including saidcurrent-winding, and a movable element subjected to the action of saidmotive sets of windings, substantially as described.

6. In a device of the class described, the

combination with two or more armatures con-- pled together, of a currentand a pressure winding in inductive relation with each of saidarmatures, said pressure-winding being connected with a circuit carryinga current with a phase ninety degrees behind that of the circuitincluding the current-winding and means extraneous to thepressure-winding circuit for maintaining this phase relation be-' tweenthe current in the pressure-coil and the electromotive force of thecircuit including the current-coil, substantially as described.

7. In a device of the class described, the combination with two or morearmatures coupled together, of a current and a pressure winding ininductive relation with each of said armatures, said pressure-windingbeing connected with a circuit carrying a current with a phase ninetydegrees behind that of the circuit including the current-winding, a

pled together, of a current and a pressure winding in inductive relationwith each of said armatures, said pressure-winding being connected witha circuit carrying a'current with a phase ninety degrees behind that ofthe circuit including the current-winding, and

a transformer having its primary connected in shunt of a circuitincluding the currentwinding, and arwinding and an adjustable resistancein circuit with'the secondary of said transformer and adapted tomaintainthe magnetism of the pressure-winding inqu'adratu're with theelectromotive force ofthe circuit including the current-winding, substantially as described;

19'. In a device of the class described, the combination with two ormorearmatures coupled together, of a current and a pressure winding ininductiverelation'with 'each of said armatures, said pressure-windingbeing connected'with a circuit different from-that including thecurrent-winding, and means extraneous to the pressure-windingcircuit'for securing and maintaining a'lagof ninetydegrees between themagnetism of the pressurewinding and the electromotive force of thecircuit including the current-coil,"substantially as described.

pled together, of a current and a pressure winding in inductive relationwith each of'the said armatures, said pressure-winding being connectedwith a circuit different from that including the current-winding,atransformer having its primary connected in shunt of a'circuitincluding the current-winding, and a L p 1 z 5 10. In 'a deviceof the class described, the combination with two or more armatures couWinding in the circuit with the secondary of the said transformer andassociated with the said pressure-winding, whereby the resultantmagnetism of pressure-windingis maintained in quadrature with theelectromagnet force of the circuit including the current-winding,substantially as described.

11. In a polyphase-current meter, the combination with two motormembers, each having current and pressure windings for association withthe circuit, of transformers having their primaries connected inparallel in circuits including said current-windings, and auxiliarypressure-windings in the secondary circuits of said transformers adaptedto secure the desired modification of the phase of the magnetism due tothe pressure-windings, the main pressure-windings receiving current fromcircuits respectively difierent from those supplying their associatedauxiliary pressure-windings, substantially asdescribed. 1

12. In a device of the class described, the combination withcurrent-windings, of prossure-windings each included in a circuitdifferent from that including the corresponding current-winding, meansextraneous to the pressure -winding circuits-for securing andmaintaining the desired phase relation between the magnetism of thepressure-winding and the electromotive force of the circuit includingthe corresponding current-winding and a movable element subject to theactions of said windings, substantially as described.

13. In a device of the class described, the combination withcurrent-windings, of pressure-windings, each included in a circuitdifferent from that including the corresponding current-winding, atransformer associated with each pressure-winding, the primary of eachtransformer receiving current from the circuit including thecurrent-Winding corresponding to the pressure-winding associated withthe transformer, and a secondary pressure-winding in each secondarytransformercircuit each of the first aforesaid pressurewindings beingoperatively associated with a secondary pressure-winding whereby thedesired modification of the phase of the magnetism due to thepressure-windings may be secured, substantially as described.

14. In a motor, the combination with current and pressure windingsthereof, a transformer, and an auxiliary pressure-winding operativelyassociated with theaforesaid pres sure-winding to modify the phase ofthe magnetism due thereto and receiving current from the secondary ofsaid transformer, the first aforesaid pressurewinding receiving currentfrom a circuit different from that sup plying current to the primary ofsaid transformer, substantially as described.

In Witness whereof I hereunto subscribe my name this 13th day ofSeptember, A. D. 1899 THOMAS DUNCAN.

W'itnesses:

CHARLES A. BROWN, GEORGE L. CRAGG.

